Evidence of cooperative effect on the enhanced superconducting transition temperature at the FeSe/SrTiO3 interface

Q Song; T L Yu; X Lou; B P Xie; H C Xu; C H P Wen; Q Yao; S Y Zhang; X T Zhu; J D Guo; R Peng; D L Feng

doi:10.1038/s41467-019-08560-z

Evidence of cooperative effect on the enhanced superconducting transition temperature at the FeSe/SrTiO₃ interface

Nat Commun. 2019 Feb 15;10(1):758. doi: 10.1038/s41467-019-08560-z.

Authors

Q Song^{1

2

3}, T L Yu^{1

2

3}, X Lou^{1

2

3}, B P Xie², H C Xu^{1

2

3}, C H P Wen^{1

2

3}, Q Yao^{1

2

3}, S Y Zhang^{4

5}, X T Zhu^{4

5}, J D Guo^{4

5

6}, R Peng^{7

8

9}, D L Feng^{10

11

12}

Affiliations

¹ State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.
² Laboratory of Advanced Materials, Fudan University, 200438, Shanghai, China.
³ Collaborative Innovation Center of Advanced Microstructures, 210093, Nanjing, China.
⁴ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.
⁵ School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
⁶ Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China.
⁷ State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China. pengrui@fudan.edu.cn.
⁸ Laboratory of Advanced Materials, Fudan University, 200438, Shanghai, China. pengrui@fudan.edu.cn.
⁹ Collaborative Innovation Center of Advanced Microstructures, 210093, Nanjing, China. pengrui@fudan.edu.cn.
¹⁰ State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China. dlfeng@fudan.edu.cn.
¹¹ Laboratory of Advanced Materials, Fudan University, 200438, Shanghai, China. dlfeng@fudan.edu.cn.
¹² Collaborative Innovation Center of Advanced Microstructures, 210093, Nanjing, China. dlfeng@fudan.edu.cn.

Abstract

At the interface between monolayer FeSe films and SrTiO₃ substrates the superconducting transition temperature (T_c) is unexpectedly high, triggering a surge of excitement. The mechanism for the T_c enhancement has been the central question, as it may present a new strategy for seeking out higher T_c materials. To reveal this enigmatic mechanism, by combining advances in high quality interface growth, ¹⁶O [Formula: see text] ¹⁸O isotope substitution, and extensive data from angle resolved photoemission spectroscopy, we provide striking evidence that the high T_c in FeSe/SrTiO₃ is the cooperative effect of the intrinsic pairing mechanism in the FeSe and interactions between the FeSe electrons and SrTiO₃ phonons. Furthermore, our results point to the promising prospect that similar cooperation between different Cooper pairing channels may be a general framework to understand and design high-temperature superconductors.

Publication types

Research Support, Non-U.S. Gov't